“Stability” as used in this description and in any appended claims refers to the mechanical condition of an operating position or attitude of a mechanical system with respect to which the system will naturally return if the system is perturbed away from the operating position or attitude in any respect.
The term “dynamically stabilized transporter” refers, in this application, to a device for personal locomotion or support of a person or equipment in a fixed position, which device has a control system that is capable of actively maintaining the stability of the transporter during operation of the transporter. The control system maintains stability of the transporter by continuously sensing the orientation, and/or changes in the orientation, of the transporter, determining the corrective action to maintain stability, and commanding the wheel motors to make the corrective action. Such a transporter is described, for example, in U.S. Pat. No. 5,971,091 (Kamen et al., issued Oct. 26, 1999), which is incorporated herein by reference.
A wide range of vehicles and methods are known for supporting or transporting human subjects. Typically, such vehicles or supports rely upon static stability, being designed so as to be stable under all foreseen conditions of placement of their ground-contacting members. Thus, for example, the gravity vector acting on the center of gravity of an automobile passes between the points of ground contact of the automobile's wheels, the suspension keeping all wheels on the ground at all times, and the automobile is thus stable. Another example of a statically stable vehicle is the stair-climbing vehicle described in U.S. Pat. No. 4,790,548 (Decelles et al.).